The BT Home Hub and certain Voyager routers contain code that is covered by the GNU General Public

MDRR algorithm in C++ for the CISCO routers.

　在路由协议刚刚开始启动时，只知道到直连网络的距离。接着，每一个路由器只会和相邻的路由器交换信息。-In the routing protocol has just started, only to know the distance to the Direct Connect network. Then, each router and neighboring routers will only exchange information.